I want to deal with macro photography. I have a NIKON D7000 and would like a help on how to start looking for a macro lens. A few questions...
1. What specifications should I look for the candidate macro lens?
2. what exactly does a flash ring do and in which cases should one be used?
3. is it limited to mounting on specific lenses?
4. I've noticed there are lenses with large / small diameters etc. For example, in practice what distinguishes a lens Nikon AFS 105mm F2.8 VR from a Nikon AF-D 60mm f / 2.8 micro?